When a fire fighting system is installed in an interior part of a building, vessel or tunnel it is normally desirable to mount the spray heads at positions close to a ceiling. This is due to aesthetic as well as practical reasons, since spray heads arranged at a distance from a ceiling are normally in the way with respect to the normal use of the room. However, sometimes it is not possible to mount the spray heads immediately adjacent to a ceiling. This is, for example, the case when bearing structures, iron girders, pipes, ventilating plant, lamps etc., are located at positions at or near the ceiling. The problem is often seen in warehouses, sheds, garages, basements, vessels, tunnels etc. In this case the spray heads must be arranged further away from the ceiling than the bearing structure, lamps, pipes etc., since the bearing structure, lamp, pipes etc. would otherwise block a spray of fluid from a given spray head and the fire fighting system would not be able to operate in a correct manner. It may even be impossible for the fire fighting system to extinguish a fire under these circumstances.
Numerous implementations of spray heads for fire fighting systems have been suggested in the patent literature.
For example, FR-A-753996 discloses a spray head having a body defining a central axis and further comprising a fixation structure for fixing the spray head to a fluid supply system, a fluid inlet, a plurality of outlet holes arranged around the central axis, and a flow path between the inlet and the holes, wherein the fluid inlet is above the holes and the fluid is flowing from the inlet and down and out of the holes.
GB-A-2 438 830 discloses an apparatus for extinguishing fire in prison cells. The apparatus comprises a source of pressurized fire extinguishing agent and a manually operable lance connected to said source of fire extinguishing agent and insert able through a small inspection hole into the prison cells. The lance comprises an elongate lance tube and a nozzle head mounted to the distal end of said lance tube, said nozzle head has a size adapted to allow insertion through said hole, and said nozzle head being provided with a plurality of nozzle holes including holes directed in rearwardly inclined directions with respect to the longitudinal axis of said lance tube. An embodiment includes a nozzle head which has a rearward facing conical surface, a forward facing conical surface, a cylindrical circumferential surface and a forward facing end face, wherein all faces include nozzle holes.
EP 1 413 333 discloses a spray head having holes of various dimensions arranged in a semi-sphere. According to EP 1 413 333 holes of relatively small dimensions are arranged to fight fire occurring at a relatively large radial distance from the spray head whereas larger, and more downwardly oriented holes, are arranged to fight fire below the spray head. The holes of relatively small dimension are cylindrical in shape, whereas the downwardly oriented holes have a cylindrically shaped initial section being in fluidic communication with an essentially conically shaped outlet section.
WO 2008/034445 discloses a spray head having a body defining a central axis and further comprising a fixation structure for fixing the spray head to a fluid supply system, a fluid inlet, a plurality of outlet holes arranged around the central axis, and a flow path between the inlet and the holes, wherein the fluid inlet is above the holes and the fluid is flowing from the inlet and down and out of the holes, wherein a first set of holes are located at a larger radial distance from the central axis than a second set of holes, and wherein the second set of holes are located at a larger radial distance from the central axis than a third set of holes, and wherein the holes comprise an essentially identical expansion passage section.
WO 99/34872 discloses a holder for mounting a spray head. The holder is mounted in a ceiling, and a spray head is subsequently mounted in the holder. The spray head may be provided with a plate for hiding screws etc. used for mounting the holder to the ceiling.
The spray heads disclosed in EP 1 413 333, WO 2008/034445 and WO 99/34872 are all mounted at or close to a ceiling and are all fixed to the fluid supply system by being fixed to the underside of the supply system and do therefore all hang down from the fluid supply system.
Spray heads arranged at a distance from a ceiling and hanging down are normally in the way with respect to the normal use of the room. There is the risk that objects or persons could bump into the spray head and thereby be damaged or damage the spray head.